Brahman alone exists…this does not preclude variation.
It is like when you are dreaming at night. The whole dream arises from one consciousness. But in the dream, you think you are a single dream character and different from other dream characters. In fact, there is only consciousness. There really is no difference between the dream character you think you are and other dream characters…it is all just consciousness. All the forms in the dream are all consciousness and the variety in forms does not mean it is other than consciousness. So if you dream you are being chased down an alley, you are really chasing yourself. There is no one else there…no other.
The dream characters can be different from each other while still being the same consciousness. The dream characters need not be identical, but they are all nothing but consciousness and not other than the same consciousness…and thus identical to consciousness (it could be said).
Do not fixate on the forms…it is all just consciousness. Beyond form and yet no form (in the dream) is other than the one consciousness.